Alert archive / Florida / Tornado Watches in 1998

Tornado Watch 73

February 28, 199817 counties in Florida

The Storm Prediction Center issued this tornado watch at Feb 28, 1998, 8:30 PM EST for 17 counties in Florida. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Feb 28, 1998, 8:30 PM EST (01:30 UTC)
Expired
Mar 1, 1998, 2:00 AM EST
In force
6 hr
Issued by
the Storm Prediction Center

Counties Charlotte County, FL, Citrus County, FL, Collier County, FL, DeSoto County, FL, Glades County, FL, Hardee County, FL, Hendry County, FL, Hernando County, FL, Highlands County, FL, Hillsborough County, FL, Lee County, FL, Manatee County, FL, Pasco County, FL, Pinellas County, FL, Polk County, FL, Sarasota County, FL, Sumter County, FL

The radar

The Tampa radar (KTBW), 32 km from the middle of the area, began a volume at 01:33 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Warnings issued inside it

7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Feb 28, 9:07 PM ESTSevere Thunderstorm WarningTBWHernando48 min
Feb 28, 9:14 PM ESTSevere Thunderstorm WarningTBWPasco46 min
Feb 28, 11:35 PM ESTSevere Thunderstorm WarningTBWHillsborough45 min
Mar 1, 12:28 AM ESTSevere Thunderstorm WarningTBWHillsborough47 min
Mar 1, 12:42 AM ESTSevere Thunderstorm WarningTBWPolk63 min
Mar 1, 12:53 AM ESTTornado WarningTBWPolk47 min
Mar 1, 1:01 AM ESTSevere Thunderstorm WarningTBWHardee49 min

The nearest sounding before it

Tampa Bay, FL (KTBW), launched 00:00Z, 1.5 hours before the alert went out and 32 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Tampa Bay, FL at 00:00Z on 1998-03-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1852 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tampa Bay, FL at 00:00Z on 1998-03-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 104 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1852 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
516 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
104 m²/s²
0-3 km storm-relative helicity
136 m²/s²
Significant tornado parameter
0.9
Supercell composite
3.9

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

457 
WWUS9 KMKC 010050
SEL3  
MKC WW 010050
FLZ000-010700-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 73
STORM PREDICTION CENTER NORMAN OK
750 PM EST SAT FEB 28 1998

THE STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

   WESTCENTRAL AND SOUTHWEST FLORIDA                            
   AND ADJACENT COASTAL WATERS

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 830 PM UNTIL
200 AM EST.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 50 STATUTE MILES EAST AND WEST
OF A LINE FROM 70 MILES NORTH OF SAINT PETERSBURG FLORIDA TO 45
MILES SOUTH SOUTHEAST OF FORT MEYERS FLORIDA.

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. 
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.


DISCUSSION...UNSTABLE AIRMASS HAS SPREAD INTO WESTERN AND SOUTHERN
FL WITH EVENING SOUNDINGS INDICATING CAPES TO 2500 J/KG.  WIND
PROFILES FAVORABLE FOR SEVERE STORMS WITH STRONG MID/UPPER JET
ACROSS NRN FL.  CURRENTLY STRONG/SEVERE THUNDERSTORMS OFF W COAST
WILL BE MOVING INLAND BY 02Z WITH ISOLATED SUPERCELLS AND TORNADOS
ALONG WITH LARGE HAIL POTENTIAL AS WET BULB ZEROS ARE FAVORABLE.


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. 
MEAN STORM MOTION VECTOR 24035.


...HALES

285,0815 255,0804 255,0822 285,0833

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 1, 12:00 AM ESTSevere Thunderstorm WatchSPCBrevard, Indian River, Martin, Okeechobee, Osceola, Palm Beach and 1 more4 hr
Mar 1, 3:15 AM ESTTornado WatchSPCBrevard, Broward, Charlotte, Collier, DeSoto, Glades and 20 more6 hr
Mar 1, 9:00 AM ESTSevere Thunderstorm WatchSPCBroward, Collier, Glades, Hendry, Martin, Miami-Dade and 3 more6 hr

Nearby

Tornado Watches in Florida, 1998Every tornado watch in 1998

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.